BSI has reported £15m growth in its meetings and events business in 2009, which helped the group balance out a slump in the accommodation-booking sector.
Group managing director Trevor Elswood said this was a massive increase from the £2m growth in meetings and events that the business reported last year.
The meetings and events business now represents around a third of BSI's £155m annual group revenue.
E-on was among the new clients that contributed to the growth, while existing clients such as Dixons Group and Tesco shifted their spend into this area.
Elswood said: "The meetings and events sector has been our rising star. It has been a very tough year for the group overall but we have maintained a margin of growth, which I'm very pleased with.
"With the increasing role of procurement, clients are seeing the benefits of bringing services under one roof. They want to reduce the number of suppliers they work with and take advantage of the efficiencies that brings, and I think larger organisations that are trusted can offer greater financial security and transparency."
The group had broadened its offer to clients by consolidating separate agencies such as Olive 360, which it acquired in 2007, into a single BSI brand, said Elswood.